Pipe having a sealing ring of a thermoset emulsion

ABSTRACT

A pipe having attached to at least one end thereof a jointforming annular ring of a thermoset emulsion. The ring has a configuration to mate with another pipe whose end has a configuration to couple with the ring to form in the presence of a gasket a complete, tight-fitting pipe joint. The thermoset emulsion is a water-in-oil emulsion comprising: 1. WATER AS THE DISCONTINUOUS PHASE, 2. A POLYMERIZABLE MIXTURE AS THE CONTINUOUS PHASE, COMPRISING: A. AN UNSATURATED POLYESTER SUCH AS ONE PRODUCED BY USE OF AN ALPHA, BETA-ETHYLENICALLY UNSATURATED POLYCARBOXYLIC ACID, AND A COPOLYMERIZABLE SOLVENT SUCH AS STYRENE.

United States Patent rm 3,591,191

[72] inventors Richard A. Coderre 3,206,44] 9/1965 Bonin et a1 260/29.6X St. Louis Park; 3,237,954 3/l966 Franklin, 277/207 8 UK Robert H.Leithelser, Jordon. both of, 3,442,842 5/1969 Bonin et al. 260/29.6 X

m I A l N 2 2 FOREIGN PATENTS PP v [22] Filed Apr. 29, '9 668,250 8/1963Canada 277/207 B (45] Patented July 6, 1971 Primary ExaminerLaverne D.Geiger [73] Assignee Ashland Oil Inc. Assistant Examiner- Robert 1.Smith Houston, Tex. Attorneys-Sherman .I. Kemmer, William G. Ewert,Larry W.

(541 PIPE HAVING A SEALING RING OF A Evans and Plumley, Tyner and SandtABSTRACT: A pipe having attached to at least one end thereof ajoint-forming annular ring of a thermoset emulsion. The ring has aconfiguration to mate with another pipe whose end has a configuration tocouple with the ring to form in the presence of a gasket a complete,tight-fitting pipe joint. The thermoset emulsion is a water-in-oilemulsion comprising:

1 water as the discontinuous phase,

2. a polymerizable mixture as the continuous phase,

a. an unsaturated polyester such as one produced by use of an alpha,bcta-ethylenically unsaturated polycarboxylic acid, and acopolymerizable solvent such as styrene.

PIPE HAVING A SEALING RING OF A THERMOSET EMULSION Many types of pipes,and particularly those of the bell and spigot type, cannot be held toclose dimensions during manufacturing. This results in pipes havingdimensions which vary from pipe to pipe. Additionally, the ends of asingle pipe are frequently out of round. ln order to facilitateconnecting sections of pipe, it is conventional practice to provide eachend with a ring of hardened material having a facing surface held toclose dimensional tolerances and to obtain a leak-free joint throughincorporation of a gasket such as a rubber O-ring. In the past thesehardened rings have been constructed of a wide variety of hardenablesubstances such as melted mixtures of sulfur and silica flour andpolymerizable mixtures of unsaturated polyesters and styrene. However,these hardenable materials have not proven altogether satisfactory for awide variety of reasons.

It is therefore an object of the present invention to provide a novelpipe having thereon one or more rings having facing surfaces held toclose dimensional tolerances.

Another object of the present invention is to provide a novel method offorming a close tolerance pipe joint end.

The above and other objects are accomplished according to the presentinvention by employing as the hardenable material an unpolymerizedwater-in-oil emulsion comprising l water as the discontinuous phase, and(2) a polymerizable mixture as the continuous phase, comprising: (a) anunsaturated polyester and (b) a copolymerizable solvent such as styrene.The emulsion is polymerized in situ to form a ring of close dimensionaltolerances.

Emulsions are two-phase systems consisting of a discontinuous phase ofdiscrete droplets surrounded by a continuous phase. When the continuousphase is oil, the emulsion is termed water-in-oil." "OiLf' in thiscontext, includes organic materials which are immiscible with water andwhich otherwise meet the requirements of the "oil phase of the emulsionsdescribed herein.

The polyesters useful in the present invention are those which (l)contain ethylenic unsaturation, (2) are soluble in a vinyl monomer, and(3) form emulsions either with or without the addition of an emulsifyingagent. These polyesters can be produced by procedures well known in theart by heating at esterification temperatures polyhydric alcohol andpolycarboxylic acid a portion of which is an alpha, beta-ethylenicallyunsaturated polycarboxylic acid.

Examples of suitable polycarboxylic acids include, among others oxalic,malonic, adipic, isophthalic, tetrachlorophthalic, phthalic, theirextant anhydrides and mixtures thereof. Examples of suitable alpha,beta-ethylenically unsaturated polycarboxylid acids include, amongothers maleic, fumaric, itaconic, their extant anhydrides and mixturesthereof. These latter acids are employed in an amount sufficient torender the polyester cross linltable by a vinyl monomer, and generallycomprise from to 100, preferably to 100, weight percent of thepolycarboxylic acid.

The polyhydric alcohols which can be reacted with the polycarboxylicacids in order to give polyesters useful in the present invention arepreferably the diols, examples of which include, among others, ethyleneglycol, diethylene glycol, triethylene glycol, l, Z-propylene glycol, l,2- or 1,3- dipropylene glycol, tripropylene glycol, 1,3-propyleneglycol, l,3-butylene glycol, LZ-butylene glycol, neopentyl glycol,l,3-pentanediol, and l,5-pentanediol. Higher polyhydric alcohols such astrimethylol propane and pentaerythritol can be used in minor amountswhich do not materially alter the linear nature of the polyester. Thepolyhydric alcohols are generally employed in a stoichiometricallyequivalent or slightly excess amount with respect to the polycarboxylicacid, and generally comprise from to about 55 percent by weight of thepolyester.

Suitable copolymerizable solvents, usually vinyl monomers, are those Ihich are miscible with the polyester and which cure to form anintractible polymerized emulsion. Any vinyl monomer found to becoreactive with unsaturated polyesters can be employed. Examplesinclude, among others, vinyl aromatics such as vinyl toluene andstyrene, substituted styrenes such as alpha-methyl styrene, esters suchas ethyl acrylate, methyl acrylate, methyl methacrylate, vinyl acetate,trialkyl cyanurate, diallyl phthalate, etc., and vinyl ethers such asmethyl vinyl ether and ethyl vinyl ether, aerylonitrile methacrylamideand compatible mixtures thereof. The vinyl monomer can be employed in aweight ratio with respect to the polyester of from 1011 to 1:9, andpreferably from 3:1 to 1:2.

Although the water phase will generally be water, solutions ofnoninterfering organic and/or inorganic materials can be used. Examplesof inorganic materials include, among others, sodium hydroxide, calciumcarbonate, and sodium chloride such as sea water. Examples of organicmaterials include, among others, methyl alcohol and ethylene glycol.Many of these materials lower the freezing point of the polymerizedemulsion and impart increased freeze-thaw resistance to the thcrmosetemulsions used in the pipes of the present invention. Amounts of wateror aqueous solution from H) to 95 weight percent, preferably from 40 toweight percent and most preferably from 45 to 65 weight percent, basedon the total amount of water or aqueous solution and mixture ofpolyester and vinyl monomer, can be present in the final emulsion.

The emulsifying agent, when used, must be of the lipophilic type inorder to effect the formation of a water-imoil emulsion. Theseemulsifying agents generally have hydrophile-lipophile balance (HLB)numbers of 2 to 8 and preferably 3 to 5. Examples of such emulsifyingagents include, among others, the glycerol monostearates, sorbitansesquioleate, polyoxyethylene sorbitol oleate, and mixtures thereof.These emulsifying agents are used in the minimum amount sufficient toeffect formation of the desired emulsion and generally comprise from 0.1to l0, preferably 0.5 to 5, weight percent based on the combined weightof polyester, solvent, and water.

The oil phase can be cured by means of any free radical generatingcatalyst heretofore employed to cause addition polymerization of vinylmonomers with unsaturated polyesters. Examples of suitable catalystsinclude, among others, the organic peroxides such as methyl ethylltetone peroxide, benzoyl peroxide, and di-t-butyl peroxide, as well asthe azonitriles. The catalyst is employed in an amount sufficient tocatalyze the cross-linking reaction and cause it to proceed at thedesired rate, and generally comprises from 0.00l to l0 weight percentbased on the weight of the vinyl monomer. Promoters such as cobaltnaphthenate, dimethyl aniline, or p-dimethyl toluidine can be employedto aid generation of free radicals by the catalyst. To prevent prematuregelation, free radical traps such as hydroquinone can be employed, as iswell-known in the art. The emulsions useful in the present invention canbe formed by a wide variety of processes. in general, it is necessaryonly to put the components in a vessel and stir mechanically or by handuntil the components emulsify. In a particularly preferred method offorming the emulsion continuously, the polyester, vinyl monomer solventand promoter are premixed and placed in a first reservoir. In a secondreservoir is placed water, and in a third reservoir is placed catalyst.Each of the reservoirs is equipped with a pump at its outlet and theoutlet streams from each are metered into a mixing chamber (wherein theimpeller develops a relatively high shear) in which the three streamsare emulsified. The mixing chamber outlet is then merely equipped with adelivery tube which can be directed toward a location where the emulsionis to be cured.

The invention may be better understood by reference to the drawingswherein FIG. 1 is a longitudinal sectional view taken through a bell andspigot pipe standing on a support prior to the application of thehardenable material, and wherein FIG. 2 is a horizontal sectional viewof a portion of the bell end of one pipe connected to the spigot end ofanother pipe.

Referring now to the drawings. and in particular to FIG I. there isshown a pipe having a bell end 11 and a spigot end [2. The spigot end 12rests upon a support 13. Around the spigot end 12 is a collar mold ringl4. the surface 15 of which is of close dimensional tolerance The spacebetween the collar mold ring 14 and the spigot end 12 of the pipe 10defines a mold 16. Within the bell end ll of the pipe 10 1s a liner moldring I! having a surface I! of close dimensional tolerance The spacebetweenthe liner mold ring 17 and the bell end 11 of the pipe 10 definesa mold l9. When one of the abovedescribed unpolymerized, polymerizableemulsions is poured into the molds l6 and 19 and permitted to harden,the result will be rings having surfaces held to close tolerances.

Referring now to H6. 2, there is shown the bell end it of one pipeconnected to the spigot end 12 of another pipe. The bell end ll has aliner 20 and the spigot end 12 has a collar 21. Between the liner 20 andthe collar 21 is a gasket 22 of any resilient sealing material.

in accordance with the present invention, rings of close dimensionaltolerances in the form of either liners or collars can be applied to oneor more ends of a'pipe to form a wide variety of specif c structures andby a wide variety of methods such as .those described in US. Pat. No.1,979,470; No.

2,40] ,554; No. 2,537,659; No. 2,955,322; No. 3,219,516; and No.3,25l,603, the disclosures of which are incorporated herein byreference. The pipe can be made of clay. cement, cast iron, stone ware,petrified tile, porcelain, and the like.

The invention may be better understood by reference to the followingexamples in which all parts and percentages are by weight unlessotherwise indicated. These examples are illustrative of certainembodiments designed to teach those skilled in the art how to practicethe invention and to represent the best mode contemplated for carryingout the invention, and are not intended to limit the scope of theinvention in any manner.

EXAMPLE 1 This example illustrates the continuous production ofpolymerized water-in-oil emulsions at various water levels.

The apparatus, used in this example, consists of four electricmotor-driven pumps and piping to connect them. Three of the pumps wereconnected to the outlets of three reservoirs and serve to continuouslymeter liquid from the three reservoirs to the fourth pump, an EasternCentrit'igal Pump (3,400 r.p.m.) which was used as a high-shear mixingchamber. The three reservoirs contained, respectively, (1) a mixture ofpolyester, styrene and catalyst, (2) water and (3) promoter (dimethyltoluidine). To reservoirs (l) and (2) were connected a "Zero- Max" 0-40Or.p.m. variable speed gear drive and an Ecco proportioning pump. Toreservoir (3) was connected a "finger" pump controlled by a Zero-Max"variable speed gear drive. The contents of reservoir l) were pumpeddirectly to the mining pump while the contents of reservoir (3) werepumped into the line from reservoii (2) just before this line enters themixing pump.

A series of 6 pound pours were strength and compressive strength of madeto test the flex wherein the copolymenzable oil phase was Aropol Q-6300(an unsaturated polyester marketed by Archer Daniels Midland Co.comprising a dipropylene glycol ester of maleic anhydride) in a 50percent solution with styrene and no emulsifier. The catalyst used was ipercent benzoyl peroxide powder, and the promoter was 0.5 percentdimethyl toluidine diluted l:5 with styrene,

The polyester, styrene and benzoyl peroxide powder were premixed andtransferred to reservoir l). Water was poured into reservoir (2) and thedimethyl toluidine-styrene solution was poured into reservoir (3). TheZero-Max" units at the outlets of this three reservoirs were adjusted togive the desired percentages of oil, water and promoter, and the mixingpump was turned on. The valves to the water and polyester solution lineswere opened. When flow was detected in the delivery tube from the mixingpump, the water pump was switched on and emulsion began to flow throughthe delivery tube. Thetube was then held over 'thelcontainer to befilled. Runs were conducted at water levels of 20, 30, 40, 50, 60, andper-. cent to produce Emulsions A through 0 inclusive respectively.

EXAMPLE 2 This example illustrates the synthesis of a preferredunsaturated polyester useful in the present invention.

The following quantities of the following ingredients are combined asdescribed:

C Dlethylenc glycol Items A through C are charged to a round-bottomflask equipped with a thermometer, a mechanical stirrer, and aDean-Stark water separation trap. The flask and its contents Y areheated for 72 hours at 390 F. until water gm.) is

removed and the acid number of the reaction product has dropped to below20. The resultant polyester is termed Polyester H.

EXAMPLE 3 To this mixtureis added [.25 percent cobalt octoate, 0.5percent dimethylaniline, and 0.5 percent methyl ethyl ketone peroxide,wherein all percentages are based on the combined weight of polyesterplus styrene. Certain properties of the hardening and the hardenedemulsion are measured and polymerized emulsions 60 recorded in Columns5--l0ofTable ii.

TABLE II Additive Impact strength Styrene. Water, .IaOH, NaCi. NaI-ICOGel Hardness Shore A at- Bhrlnk- (Gardweight. weight weight weightweight time. [TPE], [PE cg nor), Polyester percent I percent 8 percentpercent percent I min. min. 5 min. 10 min. 15 min. percent lnJibs. H...60 60 0 0 23 12 160 0 65 83 2. 6 12 H 46 55 0 0 v 0. 8 22 H 50 60 20 1 a6 i2 154' 66 Bit 1. 4 4 14 H", 46 55 20 i 2. 3 12 1M 10 55 B5 0.6 l 12H.-. 50 -60 2t) 0 5 32 0.9 t2 H 50 60 20 0 3. 5 20 16s 0.9 i 14 I Basedon the combined weight 6! polyester and styrene.

1 Based on the combined weight oi polyester. styrene, and water. I Basedon the combined weight of water and additive.

t Star cracks appear. but sample did not shatter at 20 irmbs.

EXAMPLE4 This example illustrates the construction of a pipe of thepresent invention.

The emulsion described in the fourth line of Table ll is prepared andimmediately poured into molds similar to molds l6 and 19 shown inFIG. 1. After three minutes the liner mold ring 17 is removed and thepipe 10 is lifted from the support 13. The collar mold ring 14 is thenremoved by separating it into two pieces. After l5 minutes, two sectionsof such a pipe can be put together as shown in FIG. 2 with the aid of agasket 22 in the form of an O-ring to form fluidtight seal.

EXAMPLE 5 The procedure of Example 4 is repeated except that theemulsion of the fourth line of Table II is replaced respectively withemulsions A through G with similar results.

Although the invention has been described in considerable detail withreference to certain preferred embodiments thereof, it will beunderstood that variations and modifications can be effected within thespirit and scope of the invention as described above and as defined inthe appended claims.

What We claim is:

l. A pipe having attached to at least one end thereof a jointformingannular ring of a thermoset emulsion, said ring having a configurationto mate with another pipe whose end has a configuration to couple withsaid ring to form in the presence of a gasket a complete, tight-fittingpipe joint wherein said thermoset emulsion is a polymerization productof a water in oil emulsion comprising:

l. 40 to 85 percent by weight of water as the discontinuous phase,

2. 15 to 60 percent by weight of a polymerizable mixture of thecontinuous phase, comprising: a. an unsaturated polyester and b. acopolymerizable solvent, in a weight ratio of (b) to (a) within therange of l0:l to l:9, said mixture being adapted to harden to aresilient, cross-linked solid.

2. The pipe of claim 1 wherein the emulsion also contains from 0.1 to l0percent by weight of an emulsifier having an HLB value of2 to 8.

3. The pipe of claim I wherein the polymerizable mixture comprises:

a. an unsaturated linear polyester comprising the reaction product of analpha, beta-ethylenically unsaturated dicarboxylic acid and a polyhydricalcohol and b. a copolymerizable vinyl monomer solvent.

4. The pipe of claim 3 wherein the copolymerizable vinyl monomer isstyrene.

5. The pipe of claim 3 wherein the polyester is composed of from about70 to about 45 percent by weight of said unsaturated dicarboxylic acidand from about 30 to about 55 percent by weight of said polyhydricalcohol.

6. The pipe of claim 5 wherein the unsaturated dicarboxylic acid isselected from the group consisting of maleic acid, fu maric acid,itaconic acid, equivalents thereof, their extant anhydrides, andmixtures thereof.

7. The pipe of claim 5 wherein the polyhydric alcohol is selected fromthe group consisting of ethylene glycol, diethylene glycol, triethyleneglycol, l,2-propylene glycol, 1,2-dipropylene glycol, l,3-dipropyleneglycol, tripropylene glycol, Lil-propylene glycol, l,3-butylene glycol,1,2-butylene glycol, neopentyl glycol, l,3-pentanediol andl,5-pentanediol.

8. The pipe of claim 7 wherein the continuous phase further comprises afree radical catalyst.

9. The pipe of claim 1 wherein an emulsifier having an HLB value of 2 to6 is added to the continuous phase prior to emulsification.

10. The pipe of claim 9 wherein from 0.1 to l0 percent of the emulsifieris added.

1. WATER AS THE DISCONTINUOUS PHASE.
 2. A POLYMERIZABLE MIXTURE AS THECONTINUOUS PHASE, COMPRISING: (A) AN UNSATURATED POLYESTER SUCH AS ONEPRODUCED BY USE OF AN ALPHA, BETA-ETHYLENICALLY UNSATURATEDPOLYCARBOXYLIC ACID AND A COPOLYMERIZABLE SOLVENT SUCH AS STYRENE.
 2. 15to 60 percent by weight of a polymerizable mixture of the continuousphase, comprising: a. an unsaturated polyester and b. a copolymerizablesolvent, in a weight ratio of (b) to (a) within the range of 10:1 to1:9, said mixture being adapted to harden to a resilient, cross-linkedsolid.
 2. The pipe of claim 1 wherein the emulsion also contains from0.1 to 10 percent by weight of an emulsifier having an HLB value of 2 to8.
 3. The pipe of claim 1 wherein the polymerizable mixture comprises:a. an unsaturated linear polyester comprising the reaction product of analpha, beta-ethylenically unsaturated dicarboxylic acid and a polyhydricalcohol and b. a copolymerizable vinyl monomer solvent.
 4. The pipe ofclaim 3 wherein the copolymerizable vinyl monomer is styrene.
 5. Thepipe of claim 3 wherein the polyester is composed of from about 70 toabout 45 percent by weight of said unsaturated dicarboxylic acid andfrom about 30 to about 55 percent by weight of said polyhydric alcohol.6. The pipe of claim 5 wherein the unsaturated dicarboxylic acid isselected from the group consisting of maleic acid, fumaric acid,itaconic acid, equivalents thereof, their extant anhydrides, andmixtures thereof.
 7. The pipe of claim 5 wherein the polyhydric alcoholis selected from the group consisting of ethylene glycol, diethyleneglycol, triethylene glycol, 1,2-propylene glycol, 1,2-dipropyleneglycol, 1,3-dipropylene glycol, tripropylene glycol, 1,3-propyleneglycol, 1,3-butylene glycol, 1,2-butylene glycol, neopentyl glycol,1,3-pentanediol, and 1,5-pentanediol.
 8. The pipe of claim 7 wherein thecontinuous phase further comprises a free radical catalyst.
 9. The pipeof claim 1 wherein an emulsifier having an HLB value of 2 to 6 is addedto the continuous phase prior to emulsification.
 10. The pipe of claim 9wherein from 0.1 to 10 percent of the emulsifier is added.